Earth’s Temporary Second Moon: Asteroid 2024 PT5’s Two-Month Orbit Explained

An

asteroid,
about
the
size
of
a
city
bus,
will
soon
become
a
“mini-moon”
as
it
will
get
caught
in
Earth’s
gravitational
pull.
Named
2024
PT5,
this
asteroid
is
expected
to
enter
Earth’s
orbit
on
September
29,
2024,
and
will
stay
until
November
25.
While
the
term
“mini-moon”
may
sound
peculiar,
it
is
used
by
scientists
to
describe
any
small
celestial
body
temporarily
captured
by
Earth’s
gravity.
The
asteroid
was
discovered
by
the
ATLAS
(Asteroid
Terrestrial-impact
Last
Alert
System)
project
back
in
August.

Not
a
Rare
Occurrence

Mini-moons
are
not
as
rare
as
one
might
think.
These
space
objects
are
typically
small
asteroids
that
pass
close
enough
to
Earth
to
be
captured
by
its
gravity,
often
for
brief
periods.
2024
PT5
is
expected
to
stay
within
Earth’s
orbit
for
just
under
two
months
before
continuing
its
journey
through
space.
Similar
mini-moons
have
been
recorded
in
recent
years.
For
instance,
in
2020,
an
object
thought
to
be
a
mini-moon
was
later
identified
as
space
debris
from
a
1960s
rocket
launch.
However,
2024
PT5
is
believed
to
be
a
genuine
asteroid,
according
to
scientists
at
ATLAS.

A
Temporary
Flyby

Though
referred
to
as
a
mini-moon,
2024
PT5
won’t
complete
a
full
orbit
around
Earth.
Instead,
it
will
be
a
“temporarily
captured
flyby,”
circling
around
25
percent
of
the
planet’s
surface
before
heading
off
again
into
the
solar
system.
These
brief
encounters
are
common,
and
many
mini-moons
don’t
stick
around
long
enough
to
form
a
stable
orbit.

Can
You
See
It?

Unfortunately,
spotting
this
mini-moon
with
the
naked
eye
or
even
with
most
telescopes
will
be
nearly
impossible.
The
asteroid’s
magnitude,
or
brightness,
is
far
too
dim
to
be
detected
by
standard
amateur
astronomy
equipment.
Its
absolute
magnitude
is

reported
to
be
27.593,
much
fainter
than
what
can
be
observed
with
even
a
12-inch
telescope.
Only
the
most
advanced
observatories
will
be
able
to
track
this
mini-moon’s
brief
appearance.